In preparation for submission of the Alcohol Research Center (ARC) renewal application, 12/96, a pilot study is proposed: for several dependent measures of brain function, recovery towards baseline values while the breath alcohol concentration (BrAC) is maintained at 80% will be examined. BrAC clamping uses a combination of an oral loading dose and intravenous infusion of ethanol in Ringer's lactate to establish and maintain a BrAC at the target level. We have conducted similar, IRB-approved pilot studies at IUSM over the last four years, and the rationale for seeking separate IRB review of this study is based on the following changes. (1) The target level of the clamp will be 80%mg, compared to 50mg% in previous studies. (2) The dependent measures include a behavioral measure and neuropsychological measures in addition to the event-related potential and subjective high assessment scale measures we have employed in the past. (3) the subject population is drawn from the collaboration on the genetics of alcohol population. The specific aims of the present study are to demonstrate feasibility in the sample population to be proposed in the ARC application, to quantify acute tolerance to alcohol at 80mg% BrAC, to provide data for estimating the sample size required in the ARC proposal, to establish the test/retest reliability of ERP and SHAS measures at 80mg% and to examine PR and N-Psy measures for sensitivity to acute tolerance.